Análisis exergético de plantas de producción de energía

En el siguiente documento en castellano se realiza un análisis exergético de una planta de producción de potencia de ciclo convencional. El objetivo de la realización de este análisis es obtener información sobre todos los flujos de energía a los que se ven sometidos los equipos en el transcurso del ciclo y calcular los rendimientos de los equipos. El interés principal es detectar las fuentes de ineficiencia del ciclo para evitar el derroche de la energía contenida en el combustible. Su objetivo final será la búsqueda de una alternativa de mejora para el ciclo que contribuya a un aumento del rendimiento energético del mismo. Así, aparte de lograr un beneficio económico se contribuirá a la disminución de emisiones contaminantes a la atmósfera de acuerdo con el compromiso llevado a cabo en el Protocolo de Kioto.Hurrengo dokumentuan energia lortzeko instalazio baten buruzko analisi exergetikoa egiten da. Analisi honen helburua, ekipameduek jasatzen duten energia transferentzien buruzko informazioa lortzea eta haien errendimenduak kalkulatzea da. Azkeneko helburua eraginkortasunik ez duten prozesuak detektatzea da, erregaian dagoen energia alferrik ez galtzeko. Amaitzeko, zikloaren errendimendua hobetzeko hautabide bat proposatu da. Horrela, hobekuntza ekonomikoa lortuz gain, berotegi efektua sortzen duten hondakinen ekoizpena murristuko da, Kyotoren Protokoloan ezarri zen araberaz.In the following document an exergy analysis of a conventional cycle power production plant is made. The objective of conducting this analysis is to obtain information of all the energy flows to which each equipment is subjected during the course of the cycle and to calculate the performance of each equipment. The main interest is to detect the sources of inefficiency to avoid wasting the energy contained in the fuel. Its final objective will be the proposal of an alternative to improve the performance of the cycle. Thus, apart from achieving an economic benefit, it will contribute to the reduction of polluting emissions to the atmosphere in accordance with the commitment made in the Kyoto Protocol

An Efficient Maximization Algorithm With Implications in Min-Max Predictive Control

n this technical note, an algorithm for binary quadratic programs defined by matrices with band structure is proposed. It was shown in the article by T. Alamo, D. M. de la Pentildea, D. Limon, and E. F. Camacho, ldquoConstrained min-max predictive control: modifications of the objective function leading to polynomial complexity,rdquo IEEE Tran. Autom. Control , vol. 50, pp. 710-714, May 2005, that this class of problems arise in robust model predictive control when min-max techniques are applied. Although binary quadratic problems belongs to a class of NP-complete problems, the computational burden of the proposed maximization algorithm for band matrices is polynomial with the dimension of the optimization variable and exponential with the band size. Computational results and comparisons on several hundred test problems demonstrate the efficiency of the algorithm

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La Gaceta de Madrid como instrumento propagandístico de Amadeo de Saboya (1870-1873)

Amadeo de Saboya se convierte en rey de España en diciembre de 1870. Lo hace días después del asesinato de su mentor, el general Prim, y en medio de un llamado sexenio revolucionario que alcanzará su apogeo con la proclamación en 1873 de la Primera República Española. Un período de gran instabilidad que se convierte en un desafío inabarcable para un rey foráneo, desconocido por el pueblo, rechazado por una parte importante de la clase política y utilizado por intereses inmediatos por otro sector de la elite dirigente. Dadas las circunstancias, Amadeo se apoyará en el único órgano de propaganda que puede controlar directamente: La Gaceta de Madrid. Desde esa tribuna intentará reforzar su imagen pública, siendo conscientes él y los pocos que realmente están comprometidos con la flamante monarquía constitucional parlamentaria, que dada la animadversión general de la prensa del período la utilización del órgano oficial del estado es el único camino que les queda para consolidar el nuevo régimen.Amadeo of Saboya becomes king of Spain on december 1870. He took that position just a few days after general Prim, the very one that introduced him in Spain, was murdered and at the middle of a six years turmoil period which ended with the proclamation of the Spanish First Republic on 1873. Too much for a foreign king, unknown by the Spanish people, rejected by a very important slide of the political elite and used in their own interests by other politicians. Under those circumstances Amadeo will rest on the only propaganda instrument that he directly controls: Gaceta de Madrid. From the Spanish State official newspaper he will try to improve his image among the Spanish people, however he and the ones that supported that political try in the form of a constitutional monarchy alknowledged that task as more than difficult

Min–max MPC using a tractable QP problem

Min–max model predictive controllers (MMMPC) suffer from a great computational burden that is often circumvented by using approximate solutions or upper bounds of the worst possible case of a performance index. This paper proposes a computationally efficient MMMPC control strategy in which a close approximation of the solution of the min–max problem is computed using a quadratic programming problem. The overall computational burden is much lower than that of the min–max problem and the resulting control is shown to have a guaranteed stability. A simulation example is given in the paper

Min-Max MPC based on a computationally efficient upper bound of the worst case cost

Min-Max MPC (MMMPC) controllers [P.J. Campo, M. Morari, Robust model predictive control, in: Proc. American Control Conference, June 10–12, 1987, pp. 1021–1026] suffer from a great computational burden which limits their applicability in the industry. Sometimes upper bounds of the worst possible case of a performance index have been used to reduce the computational burden. This paper proposes a computationally efficient MMMPC control strategy in which the worst case cost is approximated by an upper bound based on a diagonalization scheme. The upper bound can be computed with O(n3) operations and using only simple matrix operations. This implies that the algorithm can be coded easily even in non-mathematical oriented programming languages such as those found in industrial embedded control hardware. A simulation example is given in the paper

Min-max model predictive control as a quadratic program

This paper deals with the implementation of min-max model predictive control for constrained linear systems with bounded additive uncertainties and quadratic cost functions. This type of controller has been shown to be a continuous piecewise affine function of the state vector by geometrical methods. However, no algorithm for computing the explicit solution has been given. In this paper, we show that the min-max optimization problem can be expressed as a multi-parametric quadratic program, and so, the explicit form of the controller may be determined by standard multi-parametric techniques

Natural frequency analysis of a human femur using finite elements method

Mechanical Engineering, especially at degree studies level, is basically focused on man-made components. Therefore, different mechanical components have been studied for the main engineering fields, such as energy or vehicle industries. All of those different components have been studied in detail, following their industrial process where their material and structural properties are modified to meet their specific requirements. However, to design and built all those components, human beings have always been firstly inspired by something that was already there. Therefore, a wide range of different nature features has been inspiring the different industrial inventions developed by humans. As an engineer, instead of continuing analysing any mechanical feature industrially designed, this project aim was to study a component created by nature, analysing it from an engineering point of view. And there is when human femur appears, being one essential part of our body which also allows connecting engineering with the medical field. Moreover, the complex structure and properties that femur present can bring many inspiring ideas that, again, Nature shows to Engineering.Ingeniería Mecánic

Factores exógenos y endógenos del corresponsal de guerra. Aproximación teórica para responsables de prensa de organizaciones internacionales y no gubernamentales

The environment in which military men, journalists and international and non governmental organizations’ (IO-NGO) personnel develop their work during a war or any armed conflict is already definitely more complicate than in the immediate past. That is why for any of those actors is so important to understand the mechanisms that explain how do the other relevant subjects behave in the front line and the rearguard in order to adapt and improve their performances to that changing scenario. This work focus on the specific relations established by journalists and IO and NGO press information officers. The conclusions of this paper are the result of ground work and historic library research and are linked to the author’s historical based theory about external and internal factors regarding war correspondents

Model predictive control techniques for hybrid systems

This paper describes the main issues encountered when applying model predictive control to hybrid processes. Hybrid model predictive control (HMPC) is a research field non-fully developed with many open challenges. The paper describes some of the techniques proposed by the research community to overcome the main problems encountered. Issues related to the stability and the solution of the optimization problem are also discussed. The paper ends by describing the results of a benchmark exercise in which several HMPC schemes were applied to a solar air conditioning plant.Ministerio de Eduación y Ciencia DPI2007-66718-C04-01Ministerio de Eduación y Ciencia DPI2008-0581